Automatic reverse-motion brake



vom. .4',1927.v w JNES 1,644,061

. AUTOMATIC REVERSE MOTION BRAKE Filed June 6 11925 2 Sheets-Sheet 1 .seri-9:1

v l 4 /6 l v I NV EN TOR.

-Patented Oct. 4, 1927.

UNITED STATES p 1,644,061 PATENT GFFICE.

WILLIAM JONES, F LOS ANGELES, CALIFORNIA.

,AUTOMATIC ICEV'ERSEJMIO'llIONl BRAKE.

Appiication med June 6,1925. sei-iai No. 35,416.

This invention has relation to a safety brake device particularly designed for use in connection with auto-vehicles.

An important object of this invention is to provide a simple device that may be readily applied to an auto-vehicle to prevent an accidental reverse movement when changing gears, on on a stoppage of the-vehicle. f

A further object is to provide a device in which the braking mechanism may be automatically and instantly forced into,i.nopera.

tive position on a reverse shifting movement of the transmission gears. b'

A still further Objectis to provide a device that ma be readily applied to auto-- vehicle prope ling and braking mechanisms] being in neutral.

without eiecting a mechanical change.

Briefly, an embodiment of the invention asl shown is connected to the propeller shaft oi an auto-vehicle, but it'will be understood that it may be as readily and effectively applied to a vehicles braking drums, wheels, or axle shafts. As here shown the device yconsists ol a metal housing bolted or otherwise secured to the rear end of a transmission casing, the propeller shaft passing through suitable bearings formed in the housing walls. Keyed to the propeller shaft within the housing is a flanged collar, and loosely mounted on a cam member disposed in bearings formed in the side walls of said housing isa braking dog adapted to normally engage by gravity the peripheral surface of the collar to prevent a reverse motion of the propeller shaft when changing from one forward gear to another, and to lock the car against reverse movement when the vehicle is not in operation.

Suitable toggle mechanism connected to the cam member of the brakingV dog, and to one of the transmission shifting rods is providedv for instantly forcing the dog out of locked engagement with the collar when it is desired to propel the vehicle in reverse.

gear.

In the drawings wherein certain embodiments of the invention are'disclosed by way of example:

Fig. 1 is a side elevation of an automobile engine of usual type showing the brake device applied thereto. I

Fig. 2 is a'n enlar ed longitudinal section through 'the brake evice in a locked position taken on line 2-2 of Fig. '1. f

Fig.`3 is a transverse section of the brake taken on line of 2.

Fig. 4 is' a similar View taken on line 4-4 p f Fig. 2 with the brake in an unlocked posivFig. 5 is a side elevation of the brake in air unlocked position, parts of thecasing being broken away to more clearly disclose the mechanism therein.

Fig. 6 is a sectional view of 'the upper portion of a transmission mechanism showing the gear shifting lever andits connection to the shifting rod for actuating the brake device.

Fig. 7v is a diagrammatic plan view of the shifting rods of a transmission mechanism showing the-brake operating rod connected to the first and reverse shifting rod, the same Fig. 8 is a similar view showing the first and reverse shifting rod in reverse posi tion with brake device in an unlocked position asshowu iu Fig. 5. l

Referring now to the drawing, 10 indicates an internal combustion engine of the form usually employed in connection with motor vehicles, 11 the clutch casing,.and 12 the transmission case to which is connected the usual gear shifting lever 13. The shaft 14 extending from the rear of the transmission case is connected through the universal 15 to the vehicle propeller shaft 16, all the above mechanisms being of usual 'form and as they form no part of my invention no specific description is thought to be necessary to a complete understandingof the present invention.

The auxiliary braking mechanism 20, preferably consists of a housing formed of u per and lower. sect-ions 21,22, respectively, olted or otherwise suitably secured together, Housing 2O lis secured to the rear end ofthe transmission case by means of bolts passing through the lower housing section with the shaft 14 extendin through suitable bearings 23, 24, forme in the side walls of the housing. Ke ed to the shaft 14 within the 4housing' is a anged collar 25, whose periphvery is normally engaged by the curved end Vof a brake og 26 that is pivotally haftniember 27, said mountedv on acam s cani being rotatively .mounted in bushed bearings 28, 29 of the housing.

Bra e 'dog 26, as heretofore noted, is at all times normall in contact with the brake collar 25 and w en the propeller shaft is rotating to drive the vehiclel;lforwardly, as shown by the arrow in Fig. 2, no braking outer vl msm connected to lone of the transmission' reverse gear shifting rods, and to the brake device is employed, the said mechanism being operated automatically on a reverse sh1fting movement of the gear shifting rod. This toggle mechanism preferably consists of a plunger rod 30 mounted in a bearing 31 formed in the top' wall of' section 21 of the housing, its lower end being pivotally connected'to a yoked link 32, whose free end is provided with a slot 33 through which passes apin 34 rigidly secured.in,ears 35' f formed on the upper edge of the brake dog,

the slot 33 permitting of a free upward swinging movement of the dog on a forward rotation of the propeller shaft: The upper end of plunger shaft 30 is also transversely slotted as at 36, a pin 37 secured to the lower arms 38 of a bell crank lever 39 mounted in bearings 40' formed on the housing passing therethrough, the slot permitting ofa vertical reciprocation of the plunger rod on an operation of the mechanism. Pivoted between the upper arms 41' of the lever 39 is an apertured block 42, the free end of an operating rod 43 passing therethrough, said rod being provided with a nut 44, a coiled spring 45 being interposed on the vrod between the nut and pivoted block to permit at all times of a positive locking engagement of thel brake dog with the collar. The inner end of the operating rod passes through the bore of the reverse y transmission shifting rod 46, ad'usting nutl 47, mounted on the operating r 4providing a means for maintaining the dog in an inoperative position when it is desired to manually back the vehicle, as will be more fully explained hereinafter.

i In order that the pivoted brake. dog may ibe instantl thrown out of contact with, or disengage from the collar 25 on a reverse gear shlfting movement, a link mechanism 1s employed in connection with the toggle mechanism of the device. By means of'this mechanism the brake dog will irstbe forced out of engagement with the collar 25 through the medium of the cam member27, and on a further upward movement of the plunger the brake will be raised upwardly into an inoperative position as shown in Fig. 5. The link mechanism above referred t0 preferably consists of a crank arm 49 rigidly secured to the projecting end 50 of the cam member. Pivotally secured to the 4outer end-of arm' 49 is a link 51, its free end being pivotally connected to the lower endof the plunger arm 30 through a vertically disposed slot 52 formed in the adjacent housing wall.

From the above description it is thought that the operation of the brake device will be -clearly apparent. The cam member on which the brake dog is mounted will at all times normally force the curved edge of the dog into braking engagement with the peripheral surface of the ianged collar, but as the dog is loosely mounted on the cam member it will be apparent that when the vehicle is being operated .forwardly and the collar rotating away from the dog no binding or Wedging action will occur. -When it is desired to propel the vehicle rearwardly the movement of the gear shifting rod 46 to reverse will automatically rotate the cam' member through the medium of the crank arm 48 and link 5l4 to relieve the pressure of the braking dog against the collar 25, thek toggle mechanism simultaneously swinging the dog upwardly on its pivot and clear of the rotating collar, this operation permitting of a free rotation of the propeller shaft 1n a reverse direction.l

When the vehicle is not in operation and it is desired to move the same rearwardly without starting the engine, the gear shifting rod 46 is thrown into gage the dog from the collar on the propeller shaft. As the adjusting nut 47 is spaced a suitable distance from the adjacent end of the gear shift rod 4.6, the gears may then be shifted to neutral7 without effecting a. locking movement of the dog, thus permitting a rearward movement of the vehicle without interference. When the vehicle has been moved the desired distance the shifting rod is again thrown into lirst and then back into neutraL The diagrammatic views shown in Figs. 7, 8, are intended to illustrate the pair of .gear shifting rods common to various types of transmission mechanism, the braking device operating rod being shown in connection with the shifter rod that moves thegears in to first or reverse.

reverse to disenltH) fast to said (propulsion means, a cam member mounte in bearings, a locking dog mounted. on 'said cam member its free end being normally in contact with the peripheral surface of said collar, and means to rotate the cam member to move the locking dog into an inoperative position with respect to said collar on a reverse gear shifting movement.

2. The combination of a a collar fast thereto, a braking adapted to engage said collar to prevent reverse rotation of the propeller shaft, a cam mounted for rotation, a braking dog mounted on said cam, said cam adapted to move said braking dog out of engagement with said collar to 'permit a reverse movement o the propeller shaft.

3. The combination with an auto-vehicle propeller shaft, means forrotating the same, and a gear shifting mechanism for reversing the direction of rotation l shaft, of a collar fast on said shaft, a cam propeller shaft,

'member, a-braking dog mounted on said cam member, its freeend being normally in contact with said collar to prevent vreverse rotation of said shaft when changing from one forward gear to another and' to lock the shaft from-reverse movement when the propeller shaft is not in operation, and a toggle means for automatically rendering the braking dog inoperative when the reverse. gears are brought into operation.

, for reversing the 4. The combination with an auto-vehicle rotary driving member and means for rotating the same and a gear shifting mechanism irection of rotation of said driving mechanism, of a collar fast to the rotary driving member a cam member mounted for rotation, a bra 'ng dogmounted on said cam member, the free end of said dog normally engaging the peripheral surface of said collar, whereby to prevent a r- 'verse rotation of the driving. member, an means connected controlling the reverse movement dog normally of the propeller and to the toggle to said cam member and the gear shifting mechanism for rotating the cam member to move the dog out of enagement with the collar on hlfta reverse s ing movement of the gear shlftmg mechamsm.

5. In combination with a propeller shaft.

provided with a collar concentrically fsecured thereto and gear shifting means of the propeller shaft, of a .gravity operated pivo'ted` braking dog positioned 1n engageable 'relation'to said collar, whereby reverse movement of the propeller shaft is inhibited, and means controlled by` the reverse gear shift mechanism for positively moving the braking dog out, of engagement with the collar and simultaneously swinging the do 'on its ivot when it is desired to rotate t e propeller shaft in a reverse direction. 6. A device for normally locking a propeller shaft against reverse movement comprising a collar rigidly secured in concentric relation to the propellerl shaft, a cam actuated braking dog having a curved outer end normally engaging the collar to prevent reverse movement of the propeller shaft, a toggle mechanism connected to said braking dog, and means connec to the cam mechanism for operating the same to move the dog into an inopera-V tive position when it is desired to reverse the direction of rotation of 'the propeller shaft.

7. An automobile back stop-device comrising a rotary drivin shaft having 'a colar secured in concentric relation thereon, a braking dog normally engaging said collar to'prevent reverse motion of said driving sha t, a vcam for disen agin the dog from the collar when it is esire to reverse the direction of shaft rotation, and a toggle mechanism In testimony specification.

for actuating said cam.

whereof I`have signed tov this WILLIAM AJoints.' u 

